/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.Verify.verify;
import static com.google.common.util.concurrent.Internal.toNanosSaturated;
import static java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

import java.time.Duration;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Utilities for treating interruptible operations as uninterruptible. In all cases, if a thread is
 * interrupted during such a call, the call continues to block until the result is available or the
 * timeout elapses, and only then re-interrupts the thread.
 *
 * @author Anthony Zana
 * @since 10.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Uninterruptibles
{

    // Implementation Note: As of 3-7-11, the logic for each blocking/timeout
    // methods is identical, save for method being invoked.

    /**
     * Invokes {@code latch.}{@link CountDownLatch#await() await()} uninterruptibly.
     */
    @GwtIncompatible // concurrency
    public static void awaitUninterruptibly(CountDownLatch latch)
    {
        boolean interrupted = false;
        try
        {
            while (true)
            {
                try
                {
                    latch.await();
                    return;
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code latch.}{@link CountDownLatch#await(long, TimeUnit) await(timeout, unit)}
     * uninterruptibly.
     *
     * @since 28.0
     */
    @CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
    @GwtIncompatible // concurrency
    @Beta
    public static boolean awaitUninterruptibly(CountDownLatch latch, Duration timeout)
    {
        return awaitUninterruptibly(latch, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code latch.}{@link CountDownLatch#await(long, TimeUnit) await(timeout, unit)}
     * uninterruptibly.
     */
    @CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static boolean awaitUninterruptibly(CountDownLatch latch, long timeout, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    // CountDownLatch treats negative timeouts just like zero.
                    return latch.await(remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code condition.}{@link Condition#await(long, TimeUnit) await(timeout, unit)}
     * uninterruptibly.
     *
     * @since 28.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static boolean awaitUninterruptibly(Condition condition, Duration timeout)
    {
        return awaitUninterruptibly(condition, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code condition.}{@link Condition#await(long, TimeUnit) await(timeout, unit)}
     * uninterruptibly.
     *
     * @since 23.6
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static boolean awaitUninterruptibly(Condition condition, long timeout, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    return condition.await(remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code toJoin.}{@link Thread#join() join()} uninterruptibly.
     */
    @GwtIncompatible // concurrency
    public static void joinUninterruptibly(Thread toJoin)
    {
        boolean interrupted = false;
        try
        {
            while (true)
            {
                try
                {
                    toJoin.join();
                    return;
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code unit.}{@link TimeUnit#timedJoin(Thread, long) timedJoin(toJoin, timeout)}
     * uninterruptibly.
     *
     * @since 28.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static void joinUninterruptibly(Thread toJoin, Duration timeout)
    {
        joinUninterruptibly(toJoin, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code unit.}{@link TimeUnit#timedJoin(Thread, long) timedJoin(toJoin, timeout)}
     * uninterruptibly.
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static void joinUninterruptibly(Thread toJoin, long timeout, TimeUnit unit)
    {
        Preconditions.checkNotNull(toJoin);
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;
            while (true)
            {
                try
                {
                    // TimeUnit.timedJoin() treats negative timeouts just like zero.
                    NANOSECONDS.timedJoin(toJoin, remainingNanos);
                    return;
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code future.}{@link Future#get() get()} uninterruptibly.
     *
     * <p>Similar methods:
     *
     * <ul>
     *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
     *       Futures#getDone Futures.getDone}.
     *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
     *       Futures#getChecked(Future, Class) Futures.getChecked}.
     *   <li>To get uninterruptibility and remove checked exceptions, use {@link
     *       Futures#getUnchecked}.
     * </ul>
     *
     * @throws ExecutionException    if the computation threw an exception
     * @throws CancellationException if the computation was cancelled
     */
    @CanIgnoreReturnValue
    @ParametricNullness
    public static <V extends @Nullable Object> V getUninterruptibly(Future<V> future)
            throws ExecutionException
    {
        boolean interrupted = false;
        try
        {
            while (true)
            {
                try
                {
                    return future.get();
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code future.}{@link Future#get(long, TimeUnit) get(timeout, unit)} uninterruptibly.
     *
     * <p>Similar methods:
     *
     * <ul>
     *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
     *       Futures#getDone Futures.getDone}.
     *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
     *       Futures#getChecked(Future, Class, long, TimeUnit) Futures.getChecked}.
     *   <li>To get uninterruptibility and remove checked exceptions, use {@link
     *       Futures#getUnchecked}.
     * </ul>
     *
     * @throws ExecutionException    if the computation threw an exception
     * @throws CancellationException if the computation was cancelled
     * @throws TimeoutException      if the wait timed out
     * @since 28.0
     */
    @CanIgnoreReturnValue
    @GwtIncompatible // java.time.Duration
    @Beta
    @ParametricNullness
    public static <V extends @Nullable Object> V getUninterruptibly(
            Future<V> future, Duration timeout) throws ExecutionException, TimeoutException
    {
        return getUninterruptibly(future, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code future.}{@link Future#get(long, TimeUnit) get(timeout, unit)} uninterruptibly.
     *
     * <p>Similar methods:
     *
     * <ul>
     *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
     *       Futures#getDone Futures.getDone}.
     *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
     *       Futures#getChecked(Future, Class, long, TimeUnit) Futures.getChecked}.
     *   <li>To get uninterruptibility and remove checked exceptions, use {@link
     *       Futures#getUnchecked}.
     * </ul>
     *
     * @throws ExecutionException    if the computation threw an exception
     * @throws CancellationException if the computation was cancelled
     * @throws TimeoutException      if the wait timed out
     */
    @CanIgnoreReturnValue
    @GwtIncompatible // TODO
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    @ParametricNullness
    public static <V extends @Nullable Object> V getUninterruptibly(
            Future<V> future, long timeout, TimeUnit unit) throws ExecutionException, TimeoutException
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    // Future treats negative timeouts just like zero.
                    return future.get(remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code queue.}{@link BlockingQueue#take() take()} uninterruptibly.
     */
    @GwtIncompatible // concurrency
    public static <E> E takeUninterruptibly(BlockingQueue<E> queue)
    {
        boolean interrupted = false;
        try
        {
            while (true)
            {
                try
                {
                    return queue.take();
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code queue.}{@link BlockingQueue#put(Object) put(element)} uninterruptibly.
     *
     * @throws ClassCastException       if the class of the specified element prevents it from being added
     *                                  to the given queue
     * @throws IllegalArgumentException if some property of the specified element prevents it from
     *                                  being added to the given queue
     */
    @GwtIncompatible // concurrency
    public static <E> void putUninterruptibly(BlockingQueue<E> queue, E element)
    {
        boolean interrupted = false;
        try
        {
            while (true)
            {
                try
                {
                    queue.put(element);
                    return;
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    // TODO(user): Support Sleeper somehow (wrapper or interface method)?

    /**
     * Invokes {@code unit.}{@link TimeUnit#sleep(long) sleep(sleepFor)} uninterruptibly.
     *
     * @since 28.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static void sleepUninterruptibly(Duration sleepFor)
    {
        sleepUninterruptibly(toNanosSaturated(sleepFor), TimeUnit.NANOSECONDS);
    }

    // TODO(user): Support Sleeper somehow (wrapper or interface method)?

    /**
     * Invokes {@code unit.}{@link TimeUnit#sleep(long) sleep(sleepFor)} uninterruptibly.
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static void sleepUninterruptibly(long sleepFor, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(sleepFor);
            long end = System.nanoTime() + remainingNanos;
            while (true)
            {
                try
                {
                    // TimeUnit.sleep() treats negative timeouts just like zero.
                    NANOSECONDS.sleep(remainingNanos);
                    return;
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(1,
     * timeout, unit)} uninterruptibly.
     *
     * @since 28.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static boolean tryAcquireUninterruptibly(Semaphore semaphore, Duration timeout)
    {
        return tryAcquireUninterruptibly(semaphore, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(1,
     * timeout, unit)} uninterruptibly.
     *
     * @since 18.0
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static boolean tryAcquireUninterruptibly(
            Semaphore semaphore, long timeout, TimeUnit unit)
    {
        return tryAcquireUninterruptibly(semaphore, 1, timeout, unit);
    }

    /**
     * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(permits,
     * timeout, unit)} uninterruptibly.
     *
     * @since 28.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static boolean tryAcquireUninterruptibly(
            Semaphore semaphore, int permits, Duration timeout)
    {
        return tryAcquireUninterruptibly(
                semaphore, permits, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(permits,
     * timeout, unit)} uninterruptibly.
     *
     * @since 18.0
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static boolean tryAcquireUninterruptibly(
            Semaphore semaphore, int permits, long timeout, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    // Semaphore treats negative timeouts just like zero.
                    return semaphore.tryAcquire(permits, remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
     * uninterruptibly.
     *
     * @since 30.0
     */
    @GwtIncompatible // concurrency
    @Beta
    public static boolean tryLockUninterruptibly(Lock lock, Duration timeout)
    {
        return tryLockUninterruptibly(lock, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
    }

    /**
     * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
     * uninterruptibly.
     *
     * @since 30.0
     */
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    public static boolean tryLockUninterruptibly(Lock lock, long timeout, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    return lock.tryLock(remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Invokes {@code executor.}{@link ExecutorService#awaitTermination(long, TimeUnit)
     * awaitTermination(long, TimeUnit)} uninterruptibly with no timeout.
     *
     * @since 30.0
     */
    @Beta
    @GwtIncompatible // concurrency
    public static void awaitTerminationUninterruptibly(ExecutorService executor)
    {
        // TODO(cpovirk): We could optimize this to avoid calling nanoTime() at all.
        verify(awaitTerminationUninterruptibly(executor, Long.MAX_VALUE, NANOSECONDS));
    }

    /**
     * Invokes {@code executor.}{@link ExecutorService#awaitTermination(long, TimeUnit)
     * awaitTermination(long, TimeUnit)} uninterruptibly.
     *
     * @since 30.0
     */
    @Beta
    @GwtIncompatible // concurrency
    public static boolean awaitTerminationUninterruptibly(
            ExecutorService executor, Duration timeout)
    {
        return awaitTerminationUninterruptibly(executor, toNanosSaturated(timeout), NANOSECONDS);
    }

    /**
     * Invokes {@code executor.}{@link ExecutorService#awaitTermination(long, TimeUnit)
     * awaitTermination(long, TimeUnit)} uninterruptibly.
     *
     * @since 30.0
     */
    @Beta
    @GwtIncompatible // concurrency
    @SuppressWarnings("GoodTime")
    public static boolean awaitTerminationUninterruptibly(
            ExecutorService executor, long timeout, TimeUnit unit)
    {
        boolean interrupted = false;
        try
        {
            long remainingNanos = unit.toNanos(timeout);
            long end = System.nanoTime() + remainingNanos;

            while (true)
            {
                try
                {
                    return executor.awaitTermination(remainingNanos, NANOSECONDS);
                }
                catch (InterruptedException e)
                {
                    interrupted = true;
                    remainingNanos = end - System.nanoTime();
                }
            }
        }
        finally
        {
            if (interrupted)
            {
                Thread.currentThread().interrupt();
            }
        }
    }

    // TODO(user): Add support for waitUninterruptibly.

    private Uninterruptibles()
    {
    }
}
